1. Field of the Invention
The present invention relates to a hydroxypivalyl hydroxypivalate ester plasticizer composition, and more particularly, to a hydroxypivalyl hydroxypivalate ester plasticizer composition that is used as a plasticizer for a polyvinyl chloride (PVC) resin.
2. Description of the Related Art
Polyvinyl chloride resins are polymers of vinyl chloride monomers or copolymers containing 50% or more of vinyl chloride, and are widely used resins which are manufactured by extrusion molding, injection molding, calendaring, etc. Polyvinyl chloride resins are used in a wide range of applications, such as pipes, electric wires, electrical and mechanical products, toys, films, sheets, artificial leathers, tarpaulin, tapes, food packaging, and medical products, all of which can be manufactured using the methods described above. Polyvinyl chloride resins may have various properties depending on additives such as plasticizers, stabilizer, fillers, pigments, etc, added in a proper ratio thereto.
Plasticizers added to polyvinyl chloride resins are used to provide workability, flexibility, electric insulation, adhesiveness, etc. to the polyvinyl chloride resins. Examples of such plasticizers include phthalates, adipates, and trimellitates. In particular, phthalates, such as di-ethylhexyl phthalate (DEHP), di-butyl phthalate (DBP), di-isodecyl phthalate (DIDP), butyl benzyl phthalate (BBP), and di-isononyl phthalate (DINP), and adipates such as di-2-ethylhexyl adipate (DEHA) are commonly used.
However, the US Environmental Protection Agency and the National Institute of Health Science in Japan have classified phthalates and adipates as endocrine disruptors. Accordingly, the development of a plasticizer not containing phthalates and adipates is required.
2-ethylhexanoic acid [2-{2-(2-ethylhexanoyloxy)-ethoxy}ethoxy]-ethyl ester obtained by reacting triethylene glycol with 2-ethylhexanoic acid is a plasticizer that does not contain phthalates or adipates. This compound has excellent workability in polymer resin manufacturing processes, but the obtained polymer resin has poor properties in elongation, adhesion, transparency, and the like.
An ester compound obtained by reacting neopentylglycol with butyric acid, 2-ethylhexanoic acid, etc. as an aliphatic acid has been reported for a plasticizer in Rumanian Patent No. 62655. However, the compatibility of the ester compound with respect to polyvinyl chloride resin is lower than that of phthalates, and polyvinyl chloride resin to which the ester compound has been added has low transparency, poor elongation, and poor migration resistance.